衛星画像と音響測深機を利用したアマモ場分布域の把握―霧多布港周辺海域―

Abstract

In the eastern part of Hokkaido's Kushiro Subprefecture lies Kiritappu Port, resting across two bays and connecting them with a channel. In recent years, sediments, which have accumulated in Kiritappu Port due to littoral drift, have led to the hindrance of the passage of ships at low tide. Since the accumulation of sediments in the passage will continue under the current conditions, measures against littoral drift are being considered. Such measures, however, must be environmentally friendly because Hokkai shrimp and other economically useful marine species live in and around the port as mentioned before. Under such circumstances, it was considered important to understand the distribution area of eelgrass beds before implementing countermeasures. In this study, the quantification of the distribution area was conducted through the analysis of satellite images, echo sounding, underwater photography and submersible research to gauge two-dimensional distribution. As a result, it was found that satellite images are effective in locating algae zones in shallow sea areas and echo sounding is useful in determining the presence of algae zones in sea areas with turbidity.